<template>
  <div>
    <slot></slot>
  </div>
</template>
<script>
  const prefixCls = 'ivu-collapse';

  export default {
    name: 'EhbCollapse',
    props: {
      accordion: {
        type: Boolean,
        default: false
      },
      value: {
        type: [Array, String]
      },
      simple: {
        type: Boolean,
        default: false
      }
    },
    data () {
      return {
        currentValue: this.value
      };
    },
    computed: {
      classes () {
        return [
          `${prefixCls}`,
          {
            [`${prefixCls}-simple`]: this.simple
          }
        ];
      }
    },
    mounted () {
      this.setActive();
    },
    methods: {
      setActive () {
        const activeKey = this.getActiveKey();

        this.$children.forEach((child, index) => {
          const name = child.name || index.toString();

          child.isActive = activeKey.indexOf(name) > -1;
          child.index = index;
        });
      },
      getActiveKey () {
        let activeKey = this.currentValue || [];
        const accordion = this.accordion;

        if (!Array.isArray(activeKey)) {
          activeKey = [activeKey];
        }

        if (accordion && activeKey.length > 1) {
          activeKey = [activeKey[0]];
        }

        for (let i = 0; i < activeKey.length; i++) {
          activeKey[i] = activeKey[i].toString();
        }

        return activeKey;
      },
      toggle (data) {
        const name = data.name.toString();
        let newActiveKey = [];

        if (this.accordion) {
          if (!data.isActive) {
            newActiveKey.push(name);
          }
        } else {
          let activeKey = this.getActiveKey();
          const nameIndex = activeKey.indexOf(name);

          if (data.isActive) {
            if (nameIndex > -1) {
              activeKey.splice(nameIndex, 1);
            }
          } else {
            if (nameIndex < 0) {
              activeKey.push(name);
            }
          }

          newActiveKey = activeKey;
        }

        this.currentValue = newActiveKey;
        this.$emit('input', newActiveKey);
        this.$emit('on-change', newActiveKey);
      }
    },
    watch: {
      value (val) {
        this.currentValue = val;
      },
      currentValue () {
        this.setActive();
      }
    }
  };
</script>
